1. Field of the Invention
The present invention relates to an apparatus for determining a refractive index in a large number of points p, for example 10000 points, of a physical medium.
2. Description of the Related Art
The use for example of an infra-red laser scanner raises the problem of investigating the optical path when the infra-red beam passes through a medium consisting of layers of different refractive indices. Often the approach is to ignore the refractive index of all the points through which the beam passes.